Fix changing temperature via BasicUI (#2091) (#2165)

Signed-off-by: Christian Bandowski <christian@myvm.de>

bundles/org.openhab.core.ui/src/main/java/org/openhab/core/ui/internal/items/ItemUIRegistryImpl.java

@@ -1264,6 +1264,11 @@ public class ItemUIRegistryImpl implements ItemUIRegistry {
 
             // we require the item to define a dimension, otherwise no unit will be reported to the UIs.
             if (item instanceof NumberItem && ((NumberItem) item).getDimension() != null) {
+                if (w.getLabel() == null) {
+                    // if no Label was assigned to the Widget we fallback to the items unit
+                    return ((NumberItem) item).getUnitSymbol();
+                }
+
                 String unit = getUnitFromLabel(w.getLabel());
                 if (!UnitUtils.UNIT_PLACEHOLDER.equals(unit)) {
                     return unit;

bundles/org.openhab.core.ui/src/test/java/org/openhab/core/ui/internal/items/ItemUIRegistryImplTest.java

@@ -24,6 +24,8 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.TimeZone;
 
+import javax.measure.quantity.Temperature;
+
 import org.eclipse.emf.common.util.BasicEList;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -875,4 +877,43 @@ public class ItemUIRegistryImplTest {
         defaultWidget = uiRegistry.getDefaultWidget(StringItem.class, ITEM_NAME);
         assertThat(defaultWidget, is(instanceOf(Text.class)));
     }
+
+    @Test
+    public void getUnitForWidgetForNonNumberItem() throws Exception {
+        String unit = uiRegistry.getUnitForWidget(widget);
+
+        assertThat(unit, is(""));
+    }
+
+    @Test
+    public void getUnitForWidgetWithWidgetLabel() throws Exception {
+        // a NumberItem having a Dimension must be returned
+        NumberItem item = mock(NumberItem.class);
+        when(registry.getItem(ITEM_NAME)).thenReturn(item);
+
+        doReturn(Temperature.class).when(item).getDimension();
+
+        // we set the Label on the widget itself
+        when(widget.getLabel()).thenReturn("Label [%.1f °C]");
+
+        String unit = uiRegistry.getUnitForWidget(widget);
+
+        assertThat(unit, is(equalTo("°C")));
+    }
+
+    @Test
+    public void getUnitForWidgetWithItemLabelAndWithoutWidgetLabel() throws Exception {
+        // a NumberItem having a Dimension must be returned
+        NumberItem item = mock(NumberItem.class);
+        when(registry.getItem(ITEM_NAME)).thenReturn(item);
+
+        doReturn(Temperature.class).when(item).getDimension();
+
+        // we set the UnitSymbol on the item, this must be used as a fallback if no Widget label was used
+        when(item.getUnitSymbol()).thenReturn("°C");
+
+        String unit = uiRegistry.getUnitForWidget(widget);
+
+        assertThat(unit, is(equalTo("°C")));
+    }
 }